Mobile telephones, once a rarity, are now used by a large segment of the population and continue to gain in popularity. At their introduction, of course, mobile telephones were generally too expensive to obtain for casual use or convenience, so they were only used by either those with a definite need for mobile communications or those having sufficient wealth to be able to afford such a luxury. Widespread use of mobile telephones was also limited in the past by the capacity of whatever telecommunications systems were needed to support them.
Mobile telephones are basically portable radios having both a transmitter and a receiver. Radio communication uses electromagnetic radio waves to send information from one station to another. For voice communications, a microphone on the telephone picks up the user's voice (and any other sounds present) so that it can be converted into radio waves and transmitted. These radio waves start in a standard format, but are than modulated, or changed in a way that a receiver can analyze them and convert the information thus carried into recognizable sounds. The transmitted radio signal is amplified to a power level sufficient to enable propagation to the intended receiver.
The recent increase in mobile-telephone use is attributable in part to the rapid and steady development of various technologies. The development of smaller and more efficient electrical components has made mobile telephones more portable and easier to carry around. While overall power consumption is reduced, the batteries needed for extended mobile use have decreased in size as well. All these advances have been made available to the public at a reduced cost due to both more efficient manufacturing techniques and to economies of scale that derive from the mobile telephone's increased popularity.
At this point, it should also be noted that as the terms for radio telephones, such as “cellular (or cell) phone” and “mobile phone” are often used interchangeably, they will be treated as equivalent herein. Both, however, are a sub-group of a larger family of devices that also includes, for example, certain computers and personal digital assistants (PDAs) that are also capable of wireless radio communication in a radio network. This family of devices will for convenience be referred to as “mobile stations” (regardless of whether a particular device is actually moved about in normal operation).
FIG. 1 is an illustration of a typical mobile station 100, in this case a mobile phone 100. Mobile phone 100 is a radio telecommunication device for use in a radio telecommunication network. It contains a radio transmitter and receiver (not shown) for sending transmissions to nearby base stations that are in turn connected with the main network. The network itself naturally provides for intra-network communication, and also includes gateways through which other networks, such as the public-switched telephone network (PSTN) and the Internet may be accessed.
The internal circuitry and components (not shown) of mobile phone 100 are contained in a casing, or enclosure, that typically includes two or more sections, which will sometimes herein be referred to as covers. Referring to FIG. 1, mobile phone 100 has an enclosure 101 that includes front cover 120 and back cover 122, which are removably fastened together at joint 105 when the phone is assembled. Attached battery 124 provides a portable power source, and antenna 126 aids in transmitting and receiving radio signals. A plurality of small openings 142 formed in front cover 120 serve as a port for the speaker (not shown), which is mounted beneath them. At the opposite end of mobile station 100, microphone port 144 likewise permits entry of sound directed at the actual microphone (not shown) mounted inside. Power port 146 is for plugging in an external power adaptor and headphone port 148 for connecting an external headset and perhaps a microphone for hands-free operation.
The keypad 110 is a user interface including a plurality of openings, through which protrude keys such as alphanumeric keys 111, call control keys 112 (CALL) and 113 (END), scroll key 114 and function keys 115 and 116. As their names imply, these keys perform various duties in the phone's operation, with the alphanumeric keys 111 having a standard telephone keypad role, and the function and scroll keys used in connection with display 134. That is, the function of the function and scroll keys are variable and determined by the application state that the mobile phone is in, which is often translated into a word or icon displayed next to the key on display 134. Keys having a function that may be changed in this way are often called ‘softkeys’. Other keys shown in FIG. 1 are power switch 118 and volume control key 117.
Display 134 is typically a liquid-crystal display (LCD) device. The LCD itself is protected by a plastic window pane 132, which is mounted to cover the display and protrude into window 130, an opening formed in front cover 120. As illustrated in FIG. 1, display 134 presents to the user such information as current softkey functions, telephone numbers, signal strength, and other information useful to the operation being performed. The protective window pane 132 is typically a component separate from the LCD, its chassis, and other portions of the internal assembly.
Modern mobile stations have a great many features. A feature is, generally speaking, something that can be done to or with the phone. Originally mobile stations were capable of doing little more than sending and receiving calls. It soon became evident however, that their utility could be increased if they could perform additional functions. For example, mobile telephones were provided with the ability to remember a plurality of telephone numbers so they would not have to be re-entered each time a call was made. This feature may be facilitated through the use of a speed-dial function, where activating a few keys in a certain, memorized sequence causes a remembered telephone number to be dialed. As both displays and memories improved, this feature became a directory feature, where many telephone numbers and information associated with them could be stored, and later recalled, displayed, and used through manipulation of the softkeys.
Another exemplary feature is the ability to silence the mobile station's alert that sounds each time a call is received, or to substitute a silent vibrating alert. In this way the station could be left on without the danger of interrupting a meeting, concert, or other event where ringing of a mobile station would be unwelcome. The volume of the ring can also be adjusted. Still another feature involves logging calls that have been received, missed, or dialed, so that the user can refer back to these logs, for example, for quickly returning or redialing the logged calls.
Any of these exemplary features, when present, can usually be accessed in one of several ways. First, commonly used features may be associated with a dedicated key on the mobile station such that pressing the key activates the feature, initiating its execution. But as can been seen from FIG. 1, there are already a great many keys on mobile phone 100, and adding one for each feature or option would be inconvenient, cumbersome, and impractical. For other features, a pre-determined sequence of keystrokes might also be used. The feature is then activated when the keys involved are pressed in a certain order. As the number of features continues to increase, however, the use of these memorized keystroke sequences becomes less practical.
Softkeys work especially well where a relatively large display is available, such as the display 134 shown in FIG. 1. The reason for this, of course, is that the function performed by each softkey varies, and the display can recite the action it is currently prepared to execute when it is pressed. In addition, the various mobile-station features may be logically grouped, so that they are arranged for use in accordance with a system of menus. That is, the many features available on mobile stations are not completely unrelated. They are normally susceptible to being grouped into categories in such a way that the user can first choose a category, then perhaps a subcategory, and finally the desired feature. In this case one of the softkeys may be used to scroll though the category choices, which are displayed -in turn on the display, until the desired one appears. The displayed category can be selected by pressing another key, probably a softkey. Then the subcatagories can be scrolled though in like fashion until the select key is pressed again. In this way, many organized featured can be accessed using only a scroll key and a single softkey. Although this process is in reality simply another key sequence, the presence of a display to show menu choices makes it one that is far easier to enter. The cell-phone user looking the display and busily working through a series of menu choices has become a familiar sight.
For sight-impaired users, however, the copious menu selections can become more of a burden than an advantage. Perfectly capable of making a telephone call, those who cannot read the display may have a difficult time navigating through a user interface that presents its myriad selections visually. And although the menu and softkey system has made it possible to accommodate a large number of menu choices, the large number of choices available makes it difficult for the sightless to find the one feature that they need. Key sequences can be memorized, of course, so that reference to the visual display is not necessary, but the large number of available features tends to make these sequences quite long. Naturally, it would present little difficulty to reduce the large number choices to only a few that could be more conveniently accessed, but this also removes some of the advantages that come with a feature-rich telephone.
Needed, therefore, is a user interface that allows a sight-impaired user to more quickly navigate through a large number of available feature selections. The present invention provides just such a solution.